class_docstr: 自定义数据集
code: def __len__(self):
      return len(self.images_path)
  
file_path: deep-learning-for-image-processing/pytorch_classification/tensorboard_test/my_dataset.py
imports: from tqdm import tqdm
  from PIL import Image
  import torch
  from torch.utils.data import Dataset
label_desc: Use image node_id 2 for calling the MyDataSet obj's underlying member method code with example usage: obj.__len__() and returns: len